California commanded headlines last week when Governor Jerry Brown signed a bill committing the state to go 100% renewable in its electric sector. The move is significant, as California is the most populous state, and the 5th largest economy in the world. Yet California’s move renews the debate over government commitments to 100% renewables: How exactly to meet these goals, and what are the best ways to achieve a low-carbon future?
Going 100%: A Brief History
The first policy victory for advocates of 100% renewable energy was in, of all places, the state of Hawaii. In 2015, the Hawaiian legislature passed into law a requirement to generate 100% of its energy from renewables within the electric sector by 2045. There are days when Hawaii generates 60% of its electricity from renewable energy, and the cost of importing already expensive oil made the law popular among residents.
States are not the only ones committing to 100% renewables. Cities like Madison, Wisconsin and even Salt Lake City, Utah have established ambitious renewable energy mandates as well. Even smaller cities like Lowell, Massachusetts have announced 100% plans. These efforts by cities exist among a larger movement by municipalities to address the threat of climate change. A survey released earlier this week by the US Conference of Mayors showed that 57% of cities are planning some climate action in the coming year, with 60% saying they have launched a climate policy in the past year.
It’s within this broader context that California’s commitment emerged. Last week’s new law expanded California’s previous commitment to producing 50% of electricity from renewables by 2025, and 60% by 2030. The new target will mandate California to achieve 100% by 2045 from sources like wind, solar, and hydropower. In describing the bill, the Governor and top lawmakers hoped the law would inspire other states and countries to make the transition away from fossil fuels quicker.
Although an ambitious target, the one thing the California plan lacks is a roadmap of how to actually transition to 100% renewable. It’s here that the controversy surrounding the 100% renewable energy commitment takes hold.
The Long-Road to 100%
Unlike the political debate between climate-deniers and climate-hawks that traditionally engulfs climate policy, how we achieve 100% renewable is more of a technical one. Both sides accept the fact that we need to rapidly decarbonize if we are to prevent a 2-degree increase in global temperatures. If we are to avoid this level of warming, we will need to reduce emissions by between 80% and 100% globally by 2050.
Both sides agree that achieving this level of reductions will require wide-spread electrification in every sector. Transportation, home heating, and industrial production are a few areas with the highest potential for electrification. Widespread electrification will likely grow demand for power by 150% by the middle of the century, requiring us to eliminate carbon emissions from the electricity sector as our most carbon intensive activities begin relying on the electric grid.
This means we can increase the amount of wind, solar, and hydropower to meet this demand, right?
Well, maybe. Current modeling shows that we may need additional low-carbon options to move across the finish line on 100% renewables. According to this thinking, going 100% renewable would have to include either nuclear power, natural gas with carbon capture and sequestration (CCS), or both. Meanwhile, others believe we don’t need to rely on these carbon-emitting fuels to reach commitments like those in California. Defenders of this stance also point out that the last 10 to 20% of emissions reductions will be the hardest for renewables to accomplish due to changing peak demands.
Here’s where the dispute arises. One side believes the transition to an electricity system powered entirely by renewables is possible. The other side thinks the primary goal should be net-zero carbon emissions, and not necessarily 100% renewables.
Innovation to the Rescue
Although current modeling of future energy trends offers a less than rosy picture of the ability to achieve 100% renewables, and be carbon-neutral, these current models don’t account for new technology and innovations.
As a Vox report puts it, “there are many reasons to question what models tell us about the future three, four, five decades out.” Yes, traditional modeling of our future energy mix does tend to underestimate renewables, which are an ever-growing percentage of energy supply. The more significant drawback is their inability to see the technologies and innovations that will likely dramatically change our transition to renewables.
Take for example so-called ‘smart inverters.’ These are switches that can help the grid handle fluctuations in solar power by switching automatically to respond to power overloads. Smart inverters would make rooftop solar especially an asset in promoting grid stability.
Another prominent technological innovation that falls into this category is battery storage. The emergence of mass-market electric cars will not only increase demand for electricity but also accelerate development of better and cheaper batteries. Plugged in electric cars can collectively store large amounts of solar and wind power. By interconnecting with the grid, energy stored in vehicles can also be used in the early evenings when the sun is down, but power demand is highest.
When taking into account these, and the many other yet unknown innovations, you can see the debate over how to achieve 100% renewables fade away. The concern over the ability of solar and wind to get all the way to 100% renewable by mid-century will be mitigated if storage technology and grid innovations are widespread.
Where does this leave us?
The trend of states and cities stepping up and announcing their commitment to 100% renewables isn’t dying down any time soon. With the Trump administration continuing to rollback climate measures, from methane emissions, to clean car standards, to withdrawing from the Paris accords, climate-centric states and cities are likely to contract with the President by leading in their way.
As we consider the use of a 100% renewable energy commitment as public policy we must also keep in mind how we get there. If we do not invest in the necessary innovations and technologies to get us there on solar and wind alone, then we must not deplore the possible use of low-carbon options like nuclear and CCS.